package com.artup.util;

import java.util.Map;

import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;

public class SpringContextHolder implements ApplicationContextAware {

	private static ApplicationContext applicationContext;

	/**
	 * 实现ApplicationContextAware接口的context注入函数, 将其存入静态变量.
	 */
	@Override
	public void setApplicationContext(ApplicationContext applicationContext) {
		SpringContextHolder.applicationContext = applicationContext;
	}

	public static void replaceApplicationContext(
			ApplicationContext applicationContext) {
		SpringContextHolder.applicationContext = applicationContext;
	}

	/**
	 * 取得存储在静态变量中的ApplicationContext.
	 */
	public static ApplicationContext getApplicationContext() {
		checkApplicationContext();
		return applicationContext;
	}

	/**
	 * 从静态变量ApplicationContext中取得Bean, 自动转型为所赋值对象的类型.
	 */
	@SuppressWarnings("unchecked")
	public static <T> T getBean(String name) {
		checkApplicationContext();
		return (T) applicationContext.getBean(name);
	}

	/**
	 * 从静态变量ApplicationContext中取得Bean, 自动转型为所赋值对象的类型. 如果有多个Bean符合Class, 取出第一个.
	 */
	public static <T> T getBean(Class<T> requiredType) {
		checkApplicationContext();
		return applicationContext.getBean(requiredType);
	}

	/**
	 * 清除applicationContext静态变量.
	 */
	public static void cleanApplicationContext() {
		applicationContext = null;
	}

	private static void checkApplicationContext() {
		if (applicationContext == null) {
			throw new IllegalStateException(
					"applicaitonContext未注入,请在applicationContext.xml中定义SpringContextHolder");
		}
	}

	/**
	 * 如果spring中配置多个类型的bean，则返回最后一个，如果只有一个则读取第一个。
	 * 
	 * @param key springBean的id
	 * @param clazz 对象Class类型
	 * @return T 返回对象
	 */
	public static <T> T getBeanFilterById(String key, Class<T> clazz) {

		T _t = null;
		Map<String, T> map = (Map<String, T>) SpringContextHolder.getApplicationContext().getBeansOfType(clazz);
		if (map != null) {
			for (Map.Entry<String, T> ent : map.entrySet()) {
				if (_t == null)
					_t = ent.getValue();
				if (!ent.getKey().startsWith(key)) {
					_t = ent.getValue();
				}
			}

		}
		return _t;
	}
}
